2，4－D诱导高梁结瘤与根瘤菌共生固氮的研究

Studies on sorghum for Nodulation and Symbiotic Nitrogen Fixation with Rhizobia Induced by 2,4-D

本文以植物激素２．４－Ｄ（２．４－二氯苯氧乙酸）处理高梁（甜杂１号ｓｏｒｇｈｕｍｖｕｌｇａ－ｒｅ）（终浓度为３ｐｐｍ，并接种根瘤菌（ＯＲＳ５７１），诱导根瘤茵与高梁结瘤组织共生。自１９８９年以来，多次进行实验，结果表明这种方法可以诱导高梁根系结瘤并与结瘤组织共生，表现固氮活性。本研究实验的重复性和再现性都很好。高梁在移苗后，５～７天进行处理，效果较好，一般结瘤率都超过５０％，最高可达８０％。接种后４周瘤的直径约２～８ｍｍ，制片显微镜观察，瘤组织内有大量的根瘤菌菌体，说明根瘤菌可以进入高梁根系，并在瘤内繁殖。结瘤植株经气相色谱仪乙炔还原法测定，能表达一定程度的固氮活性。

Sorghum(Sorghum vulgare)was induced to produce nodules by a trcatment of 2.4-D in 3 ppm final concentration,and Rhizobia( ORS571)as incculated into nodules forming symbiotic association and expressing activ- ity of nitrogen fixation.The tests have been made many times since 1989,and the results can be repeated.5─7days after the inducation,the nodulation rate of the treated sorghum was more than 50%,the hightest reaching 80%,The di- ameter of the nodules was about 2─3 mm 4 weeks after the inoculation,The numerous rhizobia in the nodules were observed under microscope,It is shown that the rhizobia have entered the tissue of the root nodules and multiplied Also the results from an analysis by acetylene reduction method with gas chr- omatograph(GC)showed that the nodulose plants have certain actitvity of nitrogen fixation. The new symbiosis of Rhizobia with sorghum revealed here may be important to the research on nodulation and nitrogen of non-legume plant.